+ char *saved_line;
+ int saved_point;
+ va_list argptr, argptr2;
+ static FILE *logfile = NULL;
+ static int logging = 1;
+ // time_t current_time;
+ // struct tm* tm_info;
+ // char buffer[26] = {0};
+
+ // lock this section to avoid interlacing prints from different threads
+ pthread_mutex_lock(&print_lock);
+
+ if (logging && !logfile) {
+ logfile = fopen(logfilename, "a");
+ if (!logfile) {
+ fprintf(stderr, "Can't open logfile, logging disabled!\n");
+ logging=0;
+ }
+ }
+
+ int need_hack = (rl_readline_state & RL_STATE_READCMD) > 0;
+
+ if (need_hack) {
+ saved_point = rl_point;
+ saved_line = rl_copy_text(0, rl_end);
+ rl_save_prompt();
+ rl_replace_line("", 0);
+ rl_redisplay();
+ }
+
+ va_start(argptr, fmt);
+ va_copy(argptr2, argptr);
+ vprintf(fmt, argptr);
+ printf(" "); // cleaning prompt
+ va_end(argptr);
+ printf("\n");
+
+ if (need_hack) {
+ rl_restore_prompt();
+ rl_replace_line(saved_line, 0);
+ rl_point = saved_point;
+ rl_redisplay();
+ free(saved_line);
+ }
+
+ if (logging && logfile) {
+
+ /*
+ // Obtain current time.
+ current_time = time(NULL);
+ // Convert to local time format.
+ tm_info = localtime(¤t_time);
+ strftime(buffer, 26, "%Y-%m-%d %H:%M:%S", tm_info);
+ fprintf(logfile, "%s ", buffer);
+ */
+
+ vfprintf(logfile, fmt, argptr2);
+ fprintf(logfile,"\n");
+ fflush(logfile);
+ }
+ va_end(argptr2);
+
+ if (flushAfterWrite == 1) {
+ fflush(NULL);
+ }
+ //release lock
+ pthread_mutex_unlock(&print_lock);
+}
+
+void SetLogFilename(char *fn) {
+ logfilename = fn;
+}
+
+void iceIIR_Butterworth(int *data, const size_t len){
+
+ int i,j;
+
+ int * output = (int* ) malloc(sizeof(int) * len);
+ if ( !output ) return;
+
+ // clear mem
+ memset(output, 0x00, len);
+
+ size_t adjustedLen = len;
+ float fc = 0.1125f; // center frequency
+
+ // create very simple low-pass filter to remove images (2nd-order Butterworth)
+ float complex iir_buf[3] = {0,0,0};
+ float b[3] = {0.003621681514929, 0.007243363029857, 0.003621681514929};
+ float a[3] = {1.000000000000000, -1.822694925196308, 0.837181651256023};
+
+ float sample = 0; // input sample read from array
+ float complex x_prime = 1.0f; // save sample for estimating frequency
+ float complex x;
+
+ for (i = 0; i < adjustedLen; ++i) {
+
+ sample = data[i];
+
+ // remove DC offset and mix to complex baseband
+ x = (sample - 127.5f) * cexpf( _Complex_I * 2 * M_PI * fc * i );
+
+ // apply low-pass filter, removing spectral image (IIR using direct-form II)
+ iir_buf[2] = iir_buf[1];
+ iir_buf[1] = iir_buf[0];
+ iir_buf[0] = x - a[1]*iir_buf[1] - a[2]*iir_buf[2];
+ x = b[0]*iir_buf[0] +
+ b[1]*iir_buf[1] +
+ b[2]*iir_buf[2];
+
+ // compute instantaneous frequency by looking at phase difference
+ // between adjacent samples
+ float freq = cargf(x*conjf(x_prime));
+ x_prime = x; // retain this sample for next iteration
+
+ output[i] =(freq > 0) ? 127 : -127;
+ }
+
+ // show data
+ //memcpy(data, output, adjustedLen);
+ for (j=0; j<adjustedLen; ++j)
+ data[j] = output[j];
+
+ free(output);
+}
+
+void iceSimple_Filter(int *data, const size_t len, uint8_t k){
+// ref: http://www.edn.com/design/systems-design/4320010/A-simple-software-lowpass-filter-suits-embedded-system-applications
+// parameter K
+#define FILTER_SHIFT 4
+
+ int32_t filter_reg = 0;
+ int16_t input, output;
+ int8_t shift = (k <=8 ) ? k : FILTER_SHIFT;
+
+ for (int i = 0; i < len; ++i){
+
+ input = data[i];
+ // Update filter with current sample
+ filter_reg = filter_reg - (filter_reg >> shift) + input;
+
+ // Scale output for unity gain
+ output = filter_reg >> shift;
+ data[i] = output;
+ }
projects / proxmark3-svn / blobdiff